mxc_v4l2_capture driver with gstreamer mfw_gst_v4lsrc fails at startup

[normancheung]

I am using Linux 3.0.35 FSL sdk 4.0.0 on iMX6-solo. My pipeline is an audio and video capture and mux to a MKV container and then write to filesink.

When starting the pipeline, both gst-launch or my program, will fail (fails intermittently 50/50) with timeout on this ioctl call to mxc_v4l2_capture

-- ioctl (v4l_src->fd_v4l, VIDIOC_QUERYBUF, buf)

in function mfw_gst_v4lsrc_start_capturing ()

console also log a timeout error.

Once it started the pipeline works well, no issue.

I wonder what might be the problem with the mxc_v4l2_capture device driver?  Is this timing related?

Thanks,

Norman

[joanxie]

did you use v4lsink or isink? as I konwn, isink has delay issue.

[normancheung]

This issue seems to be fixed in the latest yocto master tree.

I merged the code in, and after running a few days, I have not seen any failure at startup yet.  I looked at the code, it seems that a mutex lock is put in the Frame Buffer acquisition.  That make sense, implying that the behavior I saweaking the timing  was a deadlock situation.

Thanks

[normancheung]

Just to add more info on this post, last week I posted this:

https://community.freescale.com/message/382547#382547

but there was no reply.  But now I have traced down to mxc_v4l2_capture driver.  Some background on this issue.

Thanks